


Lover's Quarrel

by Bitter_Baristas



Category: Undertale (Video Game)
Genre: Alternate Universe - Underfell, Alternate Universe - Underswap, M/M, Underfell Papyrus, Underfell Sans, Underswap Papyrus, Underswap Sans, edgeberry, honeymustard - Freeform
Language: English
Status: Completed
Published: 2017-03-20
Updated: 2017-03-20
Packaged: 2018-10-08 12:33:09
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,305
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10386744
Author URL: https://archiveofourown.org/users/Bitter_Baristas/pseuds/Bitter_Baristas
Summary: Fell was infuriatingly suborn, but so was Sans. They were meant to be, Sans was sure of it.





	

**Author's Note:**

> This is my first attempt at crossing AU's; because Edgeberry for life. Hopefully it's not awful.

Sans knew he was not the strongest monster in the Underground. Nor was he the smartest, or the fastest. He considered himself, despite his eccentric ego, unremarkable. He would not indulge in delusions about his capabilities. Lack of innate ability was no excuse to give anything less than one hundred percent in all endeavors.

Sans was nothing if not willing to throw himself wholeheartedly into achieving his goals.

His current goal, much to the chagrin of his house guests, was to ensure comfort and safety for the alternate versions of his brother and himself.

They had appeared unexpectedly, but after the initial fighting Sans decided they simply needed to be shown hospitality. The pair originated from a harsher, deadlier world, it made sense they would react hostility towards strangers. Papyrus had been skeptical--to his credit their counterparts had tried to put a bone attack through his skull--but after Sans used his starry, pleading eyes he relented.

Triumphant, Sans explained this universe's innocuous ways and gave the newcomers a tour.

That had been months ago, and routine was slowly returning to the skeletons home. Papyrus found kinship with Red, both content to laze on the couch with their preferred condiments, cracking awful puns.

For Sans, that was part of the mission accomplished.

Fell, however, adamantly refused any kindness that came his way. Sans, equally willful, refused to stop trying. Red told him that Papyrus wasn’t himself before a cup of coffee, so Sans began to brew it each morning. While the angular skeleton had seemed pleased with the new addition to breakfast, he showed no change in attitude. Red suggested making lasagna, apparently his brothers favorite, but nothing Sans did made the scowl on Fell’s face soften.

It was discouraging, but an uphill battle was a battle worth fighting, in Sans' opinion.

That was what he told himself that morning, energetically preparing for the day.

Papyrus was already at the table, nursing a steaming cup of coffee. Sans smiled sympathetically,

“Couldn’t sleep?”

He shook his head slowly, shadows in his eye sockets deeper than usual. Sans wrapped his arms around his brothers slim frame in a tight hug. “Why don’t you go take a nap while I make breakfast?”

Papyrus rose with a yawn, arms splaying wide in a stretch.

“Good idea, bro.” he patted Sans' head as he shuffled to the stairs.

“Oh, Papy?”

The skeleton glanced back questioningly to see Sans' bright smile. “Good morning!”

A grin tugged at his teeth and Papyrus chuckled, “good morning, bro.”

Sans' smiled again before gathering the ingredients for pancakes.

While he would normally make breakfast tacos, their guests had mentioned a desire for more diversity. Red had been almost polite about it, afraid of offending the sweeter version of himself. Fell had no such qualms about rudeness and complained openly about anything that he deemed unsuitable, which happened to be the majority of Sans' cooking.

The criticism hurt, but he always managed a smile, thanking Fell for his honest opinion. It confused the taller skeleton, who would quietly mutter to himself from across the dinner table, shooting him strange looks.

Sans, the eternal optimist, knew his efforts would prevail eventually.

Keeping that in mind he whisked the batter, humming to himself.

Crisp air drenched in morning light filtered through the kitchen window, birds singing from the surrounding forest. The beautiful day only served to raise his already high spirits and Sans began to sing softly, gliding around the kitchen in a mock dance.

Engrossed, he didn’t feel the predatory eyes watching him from the den.

He turned to pour the batter into a frying pan, jolting when he saw Fell standing a few paces away. He stood eerily still, focused on Sans with uncomfortable intensity.

The smaller shifted under his gaze, mustering a smile.

“Good morning, Fell. How did you sleep?”

“Not well, with your incessant singing.” It was an unfounded attack, Sans knew, but the venom in Fell’s voice stung regardless.

The daunting skeleton stalked closer, chin jutting forward, crimson eyes narrowed. Sans' foot slid back automatically, but he did not relent.

“I’m sorry to hear that, coffee?” He gestured to the coffee pot with a flourish, grinning hopefully.

Fell’s mouth opened to retort, but he was interrupted by Red stomping into the kitchen. The stout monster heavily collapsed into a chair, folding his arms on the table and laying his head on them.

Sans giggled and poked Red’s side, “you can sleep in, you know.”

Red lifted his head to grunt, “food.”

“Of course the only reason you’re up at a reasonable hour is food, you lazybones.” Fell smacked his brother upside the head with a practiced ease that startled Sans.

Red snarled, twisting in the chair.

“Fuck off, boss, I was up late helping Stretch.”

Fell’s blinked once, a nasty grin contorting his mouth.

“You, help? Come now brother you can come up with a better excuse. Were you whoring yourself out?” Fell pushed Red mockingly, glancing to their wide eyed bystander. “Or are you embarrassed to say it in front of him?”

Hearing mention of him jolted Sans out of his stupor and he rushed between the brothers before another one of their fights could destroy the house.

“Enough of that!” he chastised, pushing Fell away. Red stared, mouth agape.

Sans puffed his chest out, “No hitting, and none of that vulgar language.”

Fell’s sharp canines curved into a grin, gloved finger jabbing Sans' sternum.

“I will treat my worthless brother however I see fit.”

In his peripherals Sans caught Red’s wince and ashamed expression. Anger, an emotion he rarely felt so fiercely, swelled in him and his brow twitched, patience waning.

“I have tried to make you comfortable here, Fell, but I will not tolerate bullying in this house. If you can’t say something nice,” He straightened, aura gathering imposingly. “Then don’t say anything at all.”

Fell glared. “Who’s going to make me, you?” he barked out an incredulous laugh. “I could dust you in one move.”

Sans met his gaze, unwavering. “I don’t want to hear anything from you unless it’s an apology for Red.”

Red choked, his bones rattling.

Stunned into silence, Fell did nothing for several moments. Sans watched him carefully, arms rising to shield his counterpart. Magic sparked at his fingertips, ready to form.

“Morning, guys.” Papyrus paused at the kitchen threshold, glancing between the three tense monsters. “Everything alright?” His relaxed tone conflicted with his eyes, swirling with vermillion magic and trained on Fell.

“Everything's fine, Papy. We were just about to have breakfast.” Sans flashed a reassuring smile.

The daggers did not leave Fell’s eyes, and the smile did not leave Sans mouth. 

. . .

Sans' shoulders slumped as he calibrated his puzzles, breakfast at the forefront of his mind. Fell was insufferable, yet some part of him desperately wished to please him. Why? That question was one Sans preferred not to dwell on. Although he suspected it had something to do with the way Papyrus held Red when they thought no one was around. The tender way they kissed on the sofa, laughing softly and basking in the others presence. Seeing them ignited something in his soul, and when he gazed up at Fell that same heat sparked in his bones. He wanted to take Fell’s sharp face in his hands and… and that was as far as the daydream went.

Sans sighed, frustration leaching the joy he usually took from working on his puzzles.

“Hey, Blueberry.” He yelped, spinning around to face Red.

“Red! What’s up?”

Red avoided his gaze and kicked the snow.

“Look, I appreciate what you did at breakfast, but I can handle boss.” 

Sans frowned. “I won’t let him hurt you.”

Red sputtered. “What are you talking about, boss doesn’t--” Sans interrupted him.

“Don’t lie to me, Red. I’ve seen the cracks on your bones, I’ve heard you crying at night, after he yells at you.”

A blush bloomed on Red’s cheeks. Sans continued, standing to his full height. “I won’t let him hurt you, Red. You’re a good person.” To emphasize his point, Sans crossed the distance between them and hugged the trembling skeleton. “I don’t know what happened in your old world, but that will not continue here. Papy and I will do whatever it takes to protect you two, even if its from each other.”

Red stared at him, astonished. Papyrus' high esteem for Sans suddenly seemed to be more than humoring. Tears formed in Red’s eye sockets and he wiped at them furiously before offering a watery smile.

“You’re somethin’ else, Blue.”

Sans struck a pose, “Of course, I am the magnificent Sans!”

Red shoved his hands in his pockets, glancing around the clearing.

“He’s not that bad, you know, he’s just not used to being… safe.”

Blue nodded, rapt attention urging Red to continue. “Heh, you really rattle his bones, Blue.”

Sans felt the heat creeping onto his cheeks and he tried to feign disinterest.

“Oh?”

Red chuckled, elaborating. “No one from our universe is nice for the hell of it. If you keep at it, you’re bound to get under his skin.” He regarded Sans calculatingly. “It’d do him some good, someone like you.”

He spun on his heel, grinning back at Sans. "My bros a numbskull, really hard headed." he gave a two fingered salute and teleported before Sans could question him. Sans bounced from foot to foot, jittering. Was Red insinuating that Fell returned his feelings?

A way of finding out popped into his head and he dashed home, puzzles forgotten.

Sans frantically threw clutter from his desks drawer, revealing a hardback hidden at the bottom.

His dating manual.

Advice relating to his current situation could surely be found in the worn pages.

Sans flipped through the pages distractedly, walking down the hall to Papyrus' room to ask for his advice as well. He bumped into a tall skeleton, mouth moving before his eyes left the book.

“Papy, I need some advice on finding out if someone--” Azure eyes trailed up a broad frame, lingering on the tantalizingly exposed hips and spine. “Likes… me.”

Fell sneered at the dumbfounded skeleton.

“Watch where you’re going, twerp.” A red gloved hand plucked the book from Sans loose grasp. He flicked the pages carelessly, pulling them from the spine. Revenge for breakfast, he reasoned.

The ridiculous blueberry stared mutely, eye lights wide and watery. Fell ripped a handful of pages out and crumpled them in Sans' face.

“A dating manual? How,” he let the pages fall one by one. “Pathetic.”

Fell smirked sadistically.

Sans' mind disconnected from his body, unbridled rage hot in his bones. A blue femur materialized in his grasp and he swung thoughtlessly, Fell narrowly dodging the attack.

“Oh, this should be good.” Fell’s smirk fueled Sans' fury and he continued swinging the bone, pushing Fell into the backyard.

Sans' magic billowed around him, a shadow falling over his normally smiling face. Fell took a fighting stance, distantly wondering if he’d underestimated the childish monster.

A wave of bones came at his chest and he laughed, deflecting them easily. Sans' mouth quirked subtly, expression smug. Fell didn’t have time to wonder why, the answer literally hitting him.

The obvious attack had been a distraction, another wave of blunt bones striking him from behind. The surprise was enough to force him onto one knee, and Fell growled.

No more games, then.

They battled aggressively, regards for safety abandoned. Sans was a greater opponent than Fell had initially credited him for and he threw himself into the fight, determined to come out the victor.

Sans was light on his feet, dodging every blow aimed for him. He summoned a bone sharpened at the end and drew his arm back, throwing it with frightening accuracy. It nicked Fell’s cheek, the wound shallow but sufficiently bringing Sans to his senses. His attention, along with his magic, dispelled.

“Oh my gosh, Fell, are you okay?”

Fell charged him, slamming the apologetic skeleton against the snowy ground. Sans yelped, his skull bouncing and bones shaking. Fire blazing in his eyes he pinned Sans wrists above his head in a crushing grip with one hand, the other seizing his slender hyoid bone.

Sans sucked in a strangled gasp, calls for his brother dying on his tongue. He trembled beneath the enraged skeleton, babbling incoherently. Fell suddenly felt Sans bones in his grip and stilled, face wiped clean of anger. His hands retracted from Sans' like they’d been burned and he scrambled off the crying monster.

They stared at each other, both shocked by their actions. Sans rose unsteadily, wobbily approaching Fell. He tenderly took Fell’s jaw in his hands, brushing away the magic seeping from the scrape on his cheek.

He gazed at the monster sadly. “I’m so sorry Fell, I hurt you.”

Fell growled and smacked his hand away.

“I was going to dust you! If I hadn’t stopped you’d be dead!”

Sans flinched guiltily. “It’s my fault, I shouldn’t have let you get to me.”

Fell sat up, his tirade silenced when two hands held his face and teeth pressed lightly against his own.

Sans' face flushed blue and he shifted uncertainly. Fell did nothing, teeth tingling.

Sans' stumbled back, crestfallen. “I’m sorry, I-I'll just go.”

Fell’s hands caught him gently, pulling him into a protective embrace.

Sans stood stiffly, tears dripping down his face, then returned the embrace with vigor. Fell chuckled, the sound vibrating in Sans skull.

“I like you, you stupid Blueberry.”

Fell didn’t need to see Sans' face to know that a brilliant smile was there, his eye lights forming tiny hearts.

“R-really?”

Fell considered stealing the confession back, playing it off as a cruel joke. The mental image of a heartbroken Sans stopped him, forcing a pink flush onto his cheeks.

“Really.”


End file.
